Cover-locking device for grease-cups



w. e. HOFMANN COVER LOCKING DEVICE FOR GREASE CUPS.

APPLlCATlON FILED OCT. 29 1918.

PatentedSept. 7, 1920.

IN VEN TOR IVDCMA/Vi/ A TTORNEYj WITNESS:

WILLIAM G. HOFMANN, OF BATTLE CREE SHERMAN, OF BATT'L K, MICHIGAN, ASSIGNGR E CREEK, MICHIGAN.

T0 HOWARD B.

COVER-LOCKING DEVICE FOR GREASE-CUPS.

Application filed October 29, 1918.

To all ill/L07, it may concern:

Be it known that I, l/VILLIAM G1 HOF- MANN, a citizen of the United States, residing at Battle Creek, in the county of Calhoun and State of Michigan, have invented certain new and useful Improvements in Cover-Locking Devices for Grease-Cups; and I hereby declare tl at the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form part of this specification.

This invention is an improvement in grease cups and its object is to provide a cup with a simple, efiective, novel means for locking the cover thereon to prevent the cover rattling off when the cup is used on vehicles or moving objects where it is subjected to jar and vibration.

The invention consists in the novel means hereinafter described and illustrated'in the accompanying drawings for locking the screw cover on the cup and preventing casual backward rotation of the cover on' the cup when the same is in use.

In said drawings:

Figure 1 is a sectional view of a grease cup with my improved cover locking device.

Fig. 2 is a top plan view of the cup detached.

Fig. 3 is an inverted plan view of the cover showing the spring attached.

Fig. 4 is a side view of the cover removed and partly broken away.

The cup 1 may be of the usual type, being shown as a drawn metal cup having a reduced threaded extension or stem 1 and an upper cylindric portion exteriorly threaded as at l for engagement with the internal threads of the cap or cover 2, which may also be of any suitable construction, and is shown as made of drawn metal. This type of grease cup is well known and needs no further particular explanation.

In the upper edge of the cup I form a series of notches 3 which are preferably made tangential instead of radial, see Fig. 2. he purpose of such tangential arrangement of the notches is hereinafter explained.

The notches 3 are adapted to be engaged by a tooth 4* formed by suitably shaping or bending the end of a helical locking spring member 4, which is approximately one complete spiral in extent but may be increased Specification of Letters Patent.

Patented Sept. 7, 1320. Serial No. 260,195.

in length if desired. The spring is preferably made of steel, as are the cup and cover.

he upper end of this locking spring 4- is securely attached to the inside of the top of the cover, being preferably electrically welded thereto as indicated at f".

The diameter of the spiral bend of the locking spring should correspond with the internal diameter of the cover so that the tooth 4 on the free extremity of the spring will lie closely adjacent the inner threaded wall of the cover. The pitch of the spiral is preferably such that when the cover is removed from the base the edge of the tooth a will be slightly within the lower edge of the cover as indicated in Fig. 4; so as to allow the cover to be readily engaged with the cup; that is, it permits the first thread,

or thread and a half, of the cup and cover to be readily engaged before the tooth begins to engage with the notches 8. If the tooth of the cover should project so that it would engage with the cup before the threads of the cover and cup are interengage-cl it would be difiicult to replace the cover upon the cup, as the spring catch would then tend to prevent the threads thereof from properly engaging.

In the device shown the cover can be Very readily engaged with the cup, but after the threads are fairly engaged the biting edge of the tooth 4 of the spring will come into operative engagement with the notches 8 and prevent casual disengagement or backing off of the cover from the cup.

By reason of the tangential arrangement of the notches 3 the rear walls of the notches (going around the cup in the direction of the threads) will offer more resistance to movement of the spring tooth than do the front walls thereof. Thus when the cover is turned to screw it on the cup the front .walls of the notches incline in a direction to facilitate the riding of the spring tooth 4 out of the notches; but on the reverse motion of the cover to unscrew it the rear walls of the notches offer greater resistance to the backward movement of the tooth and cover.

It therefore requires a greater pressure to unscrew the cover than to screw it upon the cup and thus the device effectually prevents the cover from being casually unscrewed from the cup by the jarring or shaking of the cup and cover if the cup is applied to automobiles, agricultural implements, or

other moving part whereon it would be subjected to a great deal of vibration.

The spring does not depend upon friction to hold the parts, but effectually preventscasual unscrewing of the cover and at the same time does not interfere with the screwing down of the cover upon the cap to expel the grease from the cup.

What I claim is:

1. A grease cup having an exteriorly threaded upper portion and provided with tangentially disposed notches in its upper edge; and a cover having an interiorly threaded portion adapted to engage the exteriorly threaded portion of the cup; with a helical spring inside the cover and having one end secured thereto and its other end provided with a downwardly projecting tooth adapted to ride upon the upper edge .vided with notches in the upper edge of such threaded portion; and a cover having an interiorly threaded portion adapted to engage the exteriorly threaded portion of the cup; with a helical spring having one end welded to the cover and its other end bent to form a downwardly projecting tooth adapted to ride upon the upper edge of the cover and engage the said notches when the cover is screwed onto the cup.

In testimony that I claim the foregoing as my own I aflix my signature.

WELLIAM G. HOFMANN. 

